1. Field of the Invention
Aspects of the present invention relate to a battery management system. More particularly, aspects of the present invention relate to a method for compensating a state of charge (SOC) of a battery used in a vehicle using electrical energy, and a battery management system using the method.
2. Description of the Related Art
Vehicles using internal combustion engines that use gasoline or diesel have caused serious air pollution. Accordingly, in order to reduce air pollution various efforts have recently been made to develop electric or hybrid vehicles.
An electric vehicle uses a motor powered by electrical energy that is output from a battery. Since the electric vehicle typically uses a battery pack that includes a plurality of rechargeable/dischargeable secondary cells, an electric vehicle is advantageous in that it has no emission gases and less noise.
The term hybrid vehicle commonly refers to a gasoline-electric hybrid vehicle that uses gasoline to power an internal-combustion engine and an electric battery to power an electric motor. Recently, hybrid vehicles using an internal-combustion engine and fuel cells and hybrid vehicles using a battery and fuel cells have been developed. Fuel cells directly generate electrical energy by a chemical reaction between hydrogen or hydrogen-containing fuel and oxygen, both of which are continuously provided.
Since battery performance directly affects the performance of a vehicle that uses electrical energy, it is desirable for each battery cell of a battery used in a vehicle to have an optimum performance. Also, it is desirable to provide a battery management system (BMS) to measure the voltage and current of the overall battery to efficiently manage the charging/discharging operations of each battery cell.
A problem that may arise in a battery management system is that a cumulative error may be generated when a current integration method is used to detect the state of charge (SOC) of the battery. An SOC that is inaccurate due to cumulative errors reduces the reliability of the battery management system, which causes serious problems with vehicle driving operations.
The above information disclosed in this Background section is provided for enhancement of understanding of the background of the invention. The discussion of such information is not intended to represent or suggest that such information constitutes prior art that is already known in this country to a person of ordinary skill in the art.